Outboard motors include a water propulsion device which is often powered by an internal combustion engine. In recent years, a variety of apparatus has been employed in order to improve the operating efficiency of these engines.
For example, oxygen sensors are now commonly used to measure the air/fuel ratio of the air and fuel mixture supplied to the engine. The output from the sensor is utilized to adjust the amount of air and fuel supplied to the engine at a given condition so that the engine runs smooth and the emission content is improved.
A wide variety of other sensors are also used. For example, temperature sensors measure the engine and/or coolant temperature. If the temperature of the engine becomes too high, a warning light may illuminate. Fuel and oil level sensors may be provided, along with speed, motor position and the other sensors.
The output of all of these sensors is generally provided to the memory of a processing unit. In order for the processing unit to analyze changes in the data over a length of time, an extremely large memory is required to store the data from all of the sensors over a period of time. For example, storing only one or two data set from a temperature sensor may result in a false indication of engine overheating when only a small temperature spike is being experienced. Thus, it is generally desirable to store the information provided from each of the sensors over a period of time so that the information may be compared.
In the past, a very large memory has been utilized in order to store the data from the many sensors over the long period of time. This, however, increases the cost associated with the motor.
It is an object of the present invention to provide an improved control for an engine of the type used to power an outboard motor.